Healthy Oats for Consumers and Workers

Cleaning raw oat grains removes unwanted materials that are picked up during the milling of the oats. After cooking in steam to remove the contaminants, cooked grains are then dried in multiple stages via either fluid bed dryers or rotating drum dryers. These processes, which reach temperatures of approximately 175° F - 215° F (80° C - 102° C), use indirect steam, comprised of water vapor and fibrous dust released from the outer surface of the cooked oatmeal grain.

Dried oats are then sent through a hulling process, which removes the inedible outer shell, called the hull, from the inner kernel, called the groat. The groats are then separated by size, cleaned, conditioned, and rolled out to produce oat flakes suitable for consumption.

A large oat miller was looking to reduce noise from the dryer exhaust fans as well as minimize the dust emissions generated from the cooked oatmeal grains. They contacted AAF, who recommended the RotoClone® W because of its ability to handle hot, moist gas streams and capture even the smallest of dust particulates.


The customer wanted to minimize the dust emissions generated from the cooked oatmeal grains and reduce noise from the dryer exhaust fans. Dust buildup in the ductwork from the dryer exhaust was a frequent issue. The customer had already fitted a tundish in the drains to allow plant personnel the ability to monitor and observe the primary expansion chamber drain and the secondary clean air outlet drain.


The dryer exhaust application is ideal for the RotoClone® W. The multi-bladed “turbine like” impeller is quiet as it imparts energy to the clean air. A fine water film on the impeller blades of the RotoClone® W capture even the smallest of dust particles. Unlike pulse-jet filters, which have to form a dust layer to build resistance, the RotoClone® W requires no dust build up for immediate efficiency. Not waiting for dust cake build up means that the building of residue and bypass of the dust is prevented.


After start-up, it was immediately clear that the RotoClone® W met the customer’s two major objectives. The noise emission had drastically reduced, eliminating the unpleasant pure tones. In addition, the particulate dust from the cooked oatmeal grain was minimized.